Loading dock locking system

ABSTRACT

A system for allowing a chassis for an intermodal shipping container having fittings and a floor to be secured to a loading dock is provided. The system is capable of being stowed away into the chassis when not in use, and moveable to a locking position for interfacing with the dock&#39;s restraining system when the chassis is to be secured to the loading dock.

RELATED APPLICATIONS

This application is a continuation in part of, and claims the priorityof, presently pending U.S. nonprovisional patent application Ser. No.14/921,233 filed on Oct. 23, 2015.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to a system for locking orotherwise securing a semi-trailer, a chassis for an intermodal shippingcontainer, a box truck, or another vehicle, to a loading dock. Moreparticularly the present invention relates to a system for locking orotherwise securing a semi-trailer, a chassis for an intermodal shippingcontainer, a box truck, or another vehicle, to a loading dock, that canbe stowed away into the semi-trailer, chassis, box truck, or vehicle,when not in use.

Description of Related Art

When loading a trailer, an intermodal shipping container (referred tohereafter as a “container” or “shipping container”) on a chassis, or abox truck or other vehicle, from a building, typically an elevatedloading dock is used. A trailer is an unpowered vehicle that usually hasat least a floor, pulled by a powered vehicle. A semi-trailer does nothave a front axle, and a full trailer does. A chassis for a shippingcontainer is an unpowered vehicle for transporting intermodal shippingcontainers (see below) to be pulled by a powered vehicle, but its bodyonly has a frame that includes two parallel longitudinal I beams(without a floor), and a bolster at the rear with twist locks (seebelow) at the left and right sides. A box truck is a truck with anenclosed cuboid shaped cargo area. These and other vehicles have a cargoarea that is elevated above the ground.

The loading dock allows the trailer, container on its chassis, boxtruck, or other vehicle, to be backed up to the elevated floor of theloading dock, so that the elevated cargo area can be easily loadedusing, for example, fork lifts, hand trucks, and the like. However,during such loading there is a danger that the trailer, container on itschassis, or vehicle, may roll away or otherwise move from the loadingdock. This can cause severe safety hazards and damage freight beingloaded into the trailer, container, or box truck. Therefore, it iscommon in the art to lock the trailer, chassis or box truck being loadedto the loading dock, using a loading dock restraining system. Trailersfor this type of loading typically have metal members extending downwardthat can lock to the loading docks. However, vehicles such as trailers,chassis for shipping containers, and cargo box trucks, that do not havea method to securely attach to a loading dock restraining system, areunable to economically, safely and effectively move cargo from thebuilding of the loading dock to the trailer, chassis, or box truck, andvice versa. There are loading dock restraining systems for restrainingtrailers, chassis or box trucks lacking metal members extendingdownwards, but they are expensive and complex, such as U.S. Pat. Nos.6,773,221 and 8,499,897 B2 assigned to Rite-Hite Holding Corporation,incorporated herein by reference, which provide wheel chocks or otherstructures installed in the ground that can selectively restrain thewheels of vehicles. These cannot be seen if there is deep snow on theground and cannot easily be ploughed. Also, they cannot be easily seenby the drivers and can be run over, damaging both the system and wheels.

When unloading a trailer or vehicle having an elevated storage area atlocations such as at a street side, or ground level, it is not uncommonto have an under mounted “SLIDE OUT” lift that articulates out rearwardsfrom the vehicle or trailer, then lifts and lowers freight from thevehicle's elevated storage area (called a “slideout liftgate”). However,because the slideout liftgate must be stowed underneath the storage areawhen not in use, any structure extending downward from the bodyinterferes with the liftgate's operation. Therefore, locking structuresthat allow the semi-trailer or other vehicle to be connected to aloading dock traditionally cannot be used with vehicles using a slideoutliftgate.

Therefore, what is needed is a system that can allow a trailer orvehicle with an elevated storage area to be locked to a loading dock,that can also be stowed to allow for a slideout liftgate or otherstructure to operate on the trailer or vehicle as well.

A majority of mass produced goods in the World are now manufactured infactories and then placed on pallets (palletized) for shipment tomarket. The pallets are horizontal platforms having two parallel spacedapart horizontal layers that can be handled by fork-lifts, pallet jacks,or other pallet handlers (collectively referred to as “pallethandlers”). The pallet handlers are mounted on wheels and have forksthat fit between the layers and can be raised and lowered, so that thepallets can be moved to a desired location by being raised, moved toabove the desired location, and then lowered at that location. The forksof the pallet handler can then be removed, and it can then proceed tomove the next pallet.

The pallet handlers are used to load the pallets into intermodalshipping containers of standardized dimensions that have twist lockfittings (referred to as “fittings”) having oval holes, attached at allthe containers' upper and lower corners. The containers and fittingsoften comply with standards set by the International StandardsOrganization (“ISO”). These fittings can receive twist locks (alsospecified by ISO standards), which have a portion that can be receivedin the oval holes of the fittings and then twisted, so that the twistlocks are locked and cannot be withdrawn from the fitting until they areuntwisted. Using twist locks and linings, the containers can be securelyattached to vehicles of various modes of transportation (such as trucks,trains and boats), to each other (to allow stacking), and to otherstructures, for ease of handling. The containers are called intermodalshipping containers because they are used for shipping goods usingmultiple modes of transportation, without unloading the goods from thecontainers, and they are sometimes called ISO containers because theymust meet the standards of ISO. However, intermodal containers fortrains are often different from intermodal containers for ships becausemany intermodal containers for trains may not conform to ISO standards.Many intermodal containers for trains are configured for use withproprietary chassis of specific trucking companies, to prevent use ofthose containers by competitors, especially where goods do not need tobe transported by ship. Thus, the term “container” is not limited tocontainers that comply with ISO standards, but refers to all containersthat can be attached to, and detached from, chassis.

After being loaded with pallets of goods, containers can be attached tochassis or railroad cars, having twist locks for secure attachment ofthe containers. The chassis or railroad cars are then moved by truck,rail or other means, either to their final destination (if no waterjourney is necessary) or to ports for loading onto container ships.Because the fittings are on both the upper and lower corners of thecontainers, the containers can be slacked on the container ships andsecurely attached to each other using twist locks and the fittings onthe containers. These container ships then transport the containers to aport near the final destination. At the port, the containers are thenunloaded from the container ships using cranes, and again securelyattached to chassis or railroad cars using twist locks. If thecontainers are attached to railroad cars, then the containers aretransported to railroad yards, where large forklifts remove thecontainers from the railroad cars and place them on chassis (ISOcontainers only have doors on their ends, and do not have doors on theirsides, so containers attached to railroad cars cannot be directlyunloaded at open or closed loading docks—railroad cars' couplings (forlinking to other railroad cars) prevent the containers' doors fromabutting against loading docks for unloading using pallet jacks).

The containers on chassis (either from ports or from railroad yards) arethen transported to a warehouse having a loading dock. The loading docksare usually elevated to approximately the level of the interior floor,of the container when the container is still attached to the chassis, sothat pallet handlers can move easily between the loading dock of thewarehouse and the interior of the container or railroad car, to unloadthe pallets of goods.

There is often a slight difference between the level of the loading dockand the level of the interior floor of a container, so that a ramp orother device (called a “loading dock, leveler” or “dock leveler”) isoften used to allow the pallet handlers to move easily between theloading dock and the floor of the interior of the container.

After the palletized goods are unloaded into the warehouse by personnelwho usually perform unloading work, other personnel must assign thepalletized goods to designated areas of the warehouse, called “slots.”The various types of palletized goods must then be transported to theproper assigned slots in the warehouse. This process is called“slotting.” However, the goods cannot be placed in a slot at randombecause the goods on the shelves in any particular slot must be“rotated” to preserve freshness, especially for perishable food productsand food products with expiration dales. For example, newly arrivedgoods may be placed on the top shelf of a slot, and goods to bedelivered may be “picked” from the bottom shelf of the slot. After thebottom shelf of the slot, is emptied, the goods in the higher shelveswill all be moved to the next lower shelf. This “rotation” is done toassure that all goods are fresh; otherwise, some goods may not be pickeduntil the slot has been completely emptied, which may be very rarely. Ofcourse, the warehouse must maintain the goods under good storageconditions after they have been slotted and rotated. Obviously, thisrotation of goods, and the supervision to assure that goods are properlyslotted and rotated, are costly. Warehouse discount stores, such asCostco, are able to offer goods at substantially lower costs thanconventional retail locations partly because consumers can purchasegoods at the warehouse, directly from the pallets, thus avoiding thecosts of the additional steps described below that retailers must incurto get the goods into their retail locations, ready for sale.

When goods are to be delivered to retail locations, they must be“picked,” that is, warehouse personnel must select the palletized goodsto be delivered for the particular retail locations, and must retrievethose palletized goods from the appropriate slots. The picked goods thenmust be “routed,” that is, the palletized goods for the last destinationmust be loaded into a delivery vehicle first, and the goods for thefirst destination must be loaded into the delivery vehicle last, forexample. If the goods are not routed properly, the palletized goods forthe first destination will be behind other pallets (and inaccessible)when the delivery vehicle arrives at the first destination, for example.

There are two types of loading docks in common use, “open” and “closed.”In an open loading dock, only an elevated dock floor is provided, sothat the interior of the container (and often the interior of thewarehouse) are exposed to the environment while the container is beingunloaded. However, it is strongly desired, especially when dealing withfood, that unloading take place at “closed” loading docks, in which theentire rear end of the container is sealed against the environment whilethe container is being unloaded. This normally requires that the loadingdock be structured as an elevated door in a wall, so that the side wallsand the ceiling of the container abut against the wall around theloading dock (or against or inside a sealing engagement apparatus aroundthe periphery of the loading dock) when the floor of the container abutsagainst the loading dock. Closed loading docks normally do not haverecesses to receive projections extending rearwardly from the rear endsof containers.

It is preferable that a closed loading dock also provide some kind ofsealing engagement apparatus so that the entire circumference of therear end of a container is sealingly engaged with the periphery aroundthe loading dock when the container abuts against the loading dock.Ideally, daylight should not be visible between the rear end of thecontainer and the periphery of the closed loading dock when thecontainer is being unloaded. The sealing engagement apparatus could beas simple as a gasket around the periphery of the door of the closedloading dock, or could also include more elaborate sealing mechanisms,such as telescoping shrouds or accordion pleated extensions. Regardlessof the particular structure of the sealing engagement apparatus, itshould prevent birds, rodents, insects, dust, heat, humidity and otherenvironmental contaminants from entering into the container and thewarehouse (with its stockpiled cargo from other containers) while acontainer is being unloaded. This sealing engagement apparatus isreferred to as a loading dock seal, or weather seal. Thus, it isimportant that the rear ends of conventional shipping containers besubstantially free of rearwardly extending projections so that theentire circumference of those rear ends can abut against, and sealinglyengage with, a closed loading dock.

It is not preferred to drive a container into the interior of awarehouse for unloading because it would take too much warehouse space,and because workplace rules restrict the amount of carbon monoxide andother pollutants generated by vehicles that can he introduced into aclosed work environment. Thus, containers are almost always unloaded atelevated loading docks on the outside of a warehouse, and the palletizedgoods are then brought into the warehouse from the dock using pallethandlers.

Conventionally, when a retail location or other end destination(collectively referred to as “retail location”) requires a quantity of aproduct, a number of pallets of the desired product are picked androuted in the warehouse and loaded onto a delivery truck or vehicleusing a pallet handler. The delivery truck or vehicle then is driven tothe retail location, where it is unloaded.

The delivery vehicle is usually provided with a liftgate, which providesa platform that is movable between ground level and the elevatedinterior floor of the delivery vehicle's cargo space. Conventionally,liftgates also are storable in a folded, vertical, or other compactconfiguration so that they are out of the way when not being used, suchas when the vehicle is being driven between locations. Slideoutliftgates are one of these types of liftgates.

Individual pallets are unloaded at the retail location, usually using apallet handler that may be carried by the delivery vehicle or beavailable at the retail location. The pallet handler usually picks up apallet and then moves onto the liftgate while carrying the pallet. Theliftgate then is lowered to ground level, and the pallet and pallethandler are moved off the liftgate and into the retail location. Thesesteps are repeated until the desired number of pallets have beenunloaded at the retail location. After the pallets have been unloaded,personnel at the retail location must remove the goods from the palletsand prepare and place them on display for retail sale.

Deliveries to retail locations cannot be made directly from shippingcontainers on chassis, because retail locations normally are notprovided with an elevated loading dock, so that pallets bearing theproducts cannot normally be unloaded from the container using a pallethandler. Containers are not usually provided with platform extensions orliftgates because they must be packed tightly, abutting each other, forshipment by boat. Chassis for transporting containers are not usuallyprovided with platform extensions or liftgates either, except asdescribed below.

U.S. Pat. No. 5,827,037 to Wilson, incorporated herein by reference,discloses a chassis for receiving and transporting shipping containershaving a platform extension and a liftgate that can be moved between aposition level with the platform extension and ground level, allowing apallet handler to unload palletized cargo directly from the container atvarious retail locations without an elevated loading dock. However,column 5, lines 5-8, state that the platform extension prevents thecontainer from being unloaded at a closed loading dock.

After all the pallets in a shipping container have been removed, theempty shipping container must be removed and reused. However,transporting empty shipping containers is wasteful—this problem iscalled “backhaul.”

For semi-trailers and box trucks, liftgates often cannot be used becausecompanies will not load vehicles without a dock restraint system for thesafety reasons described above. Dock restraint systems require adownwardly extending structure (“attachment point”) on the vehicle withwhich the dock restraint system can engage, and such a downwardlyextending structure would block most liftgates from operating: beforethe present invention, a vehicle could have an attachment point or aliftgate, but not both.

Because retail locations or other distribution points usually do nothave elevated loading docks, and because loaded semi-trailers or boxtrucks may not have liftgates, the goods sometimes must be unloadedmanually, by removing individual items (such as cases) from pallets andthen manually moving them across the elevated interior floor of thecontainer, then down to ground level, and then into the retail locationor other distribution point, which is highly labor intensive andinefficient. The problems of loading and unloading semi-trailers or boxtrucks that have liftgates but lack attachment points (and vice versa),including backhaul, are described in the article published athttp://www.truckinginfo.com/blog/trailer-talk/story/2016/06/lift-gate-trailers-can-load-normally-with-new-lok-devices.aspx,which is incorporated herein by reference.

In natural disasters or other scenarios, emergency and other suppliesoften can be brought into ports on shipping containers, but personnel orequipment may not be available to transport the containers to warehousesfor unloading, slotting and then later picking and delivery ofpalletized goods by delivery trucks to centers for distribution tovictims. If palletized goods could be unloaded directly from shippingcontainers, then the palletized emergency and other supplies could bedistributed directly to victims from the shipping containers, providingrelief much more quickly and easily.

Further, to address the problem of backhaul, it would be ideal tore-fill empty containers with other palletized goods as soon aspossible, so that the refilled containers can then be transported to thenext destination. However, many companies will not re-fill emptycontainers, trailers, box trucks, or other vehicles, at their elevatedloading docks, unless there is a dock restraint system, in order toavoid the problems of damage and injuries if a container on a chassis,trailer, box truck, or other vehicle, moves away from the loading dockwhile a pallet handler is loading, as described above.

Thus, there is a need for a chassis for an intermodal shipping containerthat will allow unloading of palletized goods using a pallet handlerdirectly at retail locations or other distribution points that lack anelevated loading dock (which requires use of a liftgate), yet, tominimize backhaul, can also be reloaded with palletized goods using apallet handler at both open and closed loading docks (which requires useof a dock restraint system), even though prior art dock restraintsystems prevented the use of liftgates, and prior art liftgate systemswith platform extensions could not be used at closed docks, as explainedabove.

SUMMARY OF THE INVENTION

The subject matter of this application may involve, in some cases,interrelated products, alternative solutions to a particular problem,and/or a plurality of different uses of a single system or article.

In one aspect, a loading dock locking system is provided. The loadingdock locking system is configured to be connected or otherwise installedon a vehicle or trailer or chassis to allow the vehicle/trailer/chassisto be restrained by a loading dock vehicle restraining system whichholds the vehicle/trailer/chassis in place. The loading dock lockingsystem may comprise a U-shaped member configured to be locked to aloading dock. The U-shaped member has at least one elongate arm and aperpendicular bar connected to a distal end of the elongate arm, andtherefore may not necessarily be U-shaped. However, it is referred toherein as “U-shaped” for convenience, because the presently preferredembodiment is U-shaped.

The term “U-shaped member” means and includes any attachment point orother member having at least one elongate arm and a structure forengagement, by a loading dock restraining system, such as asubstantially perpendicular bar, loop, hook or other engageablestructure (singly and collectively referred to as a “bar”).

The bar or other structure is configured to be locked to the vehiclerestraining system of the loading dock. This U-shaped member is stowablesuch that when not in use, it can be hidden away, providing both safetyand functionality enhancements to the vehicle/trailer. The U-shapedmember is movable between this stowed position and a vertical lockingposition. In the stowed position, the arm is positioned tinder or withinthe body of the vehicle or trailer or chassis, for example, such thatthe U-shaped member is oriented approximately parallel to a floor of thebody of the trailer or vehicle or chassis. In the vertical lockingposition, the arm is extended from the body and is orientedapproximately vertically downward away from the body. In the verticallocking position, the loading dock's vehicle restraining system mayinterface with the bar, thereby preventing the vehicle from accidentallymoving or shifting from the building. Indeed, in some embodiments, theloading dock locking system can be retrofitted onto existing trailers,chassis and other vehicles.

In another aspect, a method of locking a vehicle or trailer or chassisto a loading dock is provided. This method may begin with positioning avehicle and/or trailer and/or chassis have a loading dock locking systemof the present invention by a loading dock. This system may have aU-shaped member configured to be locked to a loading dock. In oneembodiment, the U-shaped member may have two elongate arms and aperpendicular bar connected to a distal end of each elongate arm, thebar being configured to be locked to a vehicle restraining system of theloading dock. The U-shaped member is movable between a stowed positionand a vertical locking position. In the stowed position, the arm ispositioned under or within the body of the vehicle or trailer orchassis, such that the U-shaped member is oriented approximatelyparallel to a floor of the body. In the vertical locking position, thearm is extended from the body and is oriented approximately verticallydownward away from the body. Preferably, the method further involvesdrawing the U-shaped member away from the rear of the trailer to anextended horizontal position. Next, the U-shaped member may be swungdownward from the extended horizontal position to the vertical lockingposition. The U-shaped member is then locked in place in this verticallocking position. The trailer or chassis or vehicle may then be backedup to abut the loading dock, and the bar may be locked to the loadingdock's vehicle restraining system.

Thus, the invention preferably comprises a chassis for an intermodalshipping container which has twist locks to engage with fittings on thecontainer and a loading dock locking system connected to the rear of thebody. The loading dock locking system comprises a U-shaped memberconfigured to be locked to a loading dock. The U-shaped memberpreferably has two elongated arms and a perpendicular bar connected to adistal end of the elongated arm, and the bar is configured to be lockedto the loading dock. The U-shaped member is movable between a stowedposition for when the liftgate is being operated for unloading at aretail location, or for loading at shippers that do not have elevatedloading docks, or when the chassis is in transport, such that the arm ispositioned under or within the body, oriented approximately parallel tothe floor of the body, and a vertical locking position for locking thechassis to the loading dock, such that the arm is extended from the bodyand is oriented approximately vertically downward away from the body. Aslideout liftgate is mounted under the body and forward of the verticallocking position, so that the U-shaped member can be moved to thevertical locking position without being blocked by the slideoutliftgate, and so that when the U-shaped member is in the stowedposition, the slideout liftgate can be deployed to provide a platformmovable between abutting the floor and the ground.

A safety braking system in communication with at least one of the wheelsof the chassis can be provided, and can be configured to activateautomatically if the U-shaped member is not in the stowed position.Activation of the safety braking system can cause at least one of thewheels to stop rotating.

The chassis can further comprise a switch in communication with thesafety braking system, to be physically actuated when the U-shapedmember is in the stowed position, the actuation of the switch preventingactivation of the safety braking system.

The chassis can further comprise an electronic sensor in communicationwith the safety braking system, the electronic sensor being positionedto be actuated when the U-shaped member is in the stowed position,preventing activation of the safety braking system.

The safety braking system can be configured to activate when theplurality of wheels are rotating above a predetermined rate.

The U-shaped member is slideable from the stowed position to an extendedhorizontal position, and only when in the extended horizontal positionis hingedly movable from the extended horizontal position to thevertical locking position about an axis at a proximal end of the arm.

The U-shaped member can be positioned below the floor of the body whenin the stowed position.

The arm can have a stowed position aperture at a distal end of the arm,and a vertical locking position aperture at a proximal end of the arm;and the chassis can have a spring loaded pin configured to fit into eachaperture, the spring loaded pin having a spring biasing it into theapertures and being movable away from the apertures, so that when movedaway, the U-shaped member may move between the stowed and verticallocking positions and when the spring loaded pits passes through theapertures, the U-shaped member is prevented from movement.

Preferably, the U-shaped member has two arms, each arm joined togetherby the bar at the distal end of each arm.

The chassis can have a gusset plate attached to a floor of the body, thearm connectable to the gusset plate when in the vertical lockingposition.

The arm can be slideable within a channel formed by a tube when movingto and from the stowed position.

The chassis can include a loading dock locking system connected to thebody at the rear, and the loading dock locking system comprises aU-shaped member configured to be locked to a loading dock. The U-shapedmember has two elongate arms and a perpendicular bar connected to adistal end of each elongate arm, the bar configured to be locked to theloading dock. The U-shaped member is movable between a stowed positionfor when the chassis is in transport, such that the arm is positionedunder or within the body, having the U-shaped member orientedapproximately parallel to a floor of the body, and a vertical lockingposition for locking the chassis to the loading dock, such that the armis extended from the body and is oriented, approximately verticallydownward away from the body. The U-shaped member is slideable from thestowed position to an extended horizontal position, and only when, inthe extended horizontal position is hingedly movable from the extendedhorizontal position to the vertical locking position about an axis at aproximal end of the arm.

A sensor can be in communication with the braking system, and positionedto be physically actuated when the U-shaped member is in the stowedposition.

The chassis can have an electronic sensor in communication with thebraking system, the switch being positioned to be physically actuatedwhen the U-shaped member is in the stowed position to prevent activationof the safety braking system.

The braking system can be configured to activate when the wheels arerotating above a predetermined rate.

Preferably, the U-shaped member is slideable from the stowed position toan extended horizontal position, and when in the extended horizontalposition is hingedly movable from the extended horizontal position tothe vertical locking position about an axis at a proximal end of thearm.

The chassis can have each arm slideable within a channel formed by atube when moving to and from the stowed position.

The invention also includes a method of locking a chassis for anintermodal shipping container to a loading dock comprising providing aloading dock locking system at a rear of the body which has a U-shapedmember configured to be locked to a loading dock (the U-shaped memberhas two elongate arms and a perpendicular bar connected to a distal endof each elongate arm, and the bar is configured to be locked to theloading dock; the U-shaped member is movable between a stowed positionfor when the chassis is in transport, such that the arm is positionedunder or within the body and having the U-shaped member orientedapproximately parallel to a floor of the body, and a vertical lockingposition for locking the chassis to the loading dock, such that the armis extended from the body and is oriented approximately verticallydownward away from the body), drawing the U-shaped member away from therear of the chassis to an extended horizontal position, swinging theU-shaped member downward from the extended horizontal position, to thevertical locking position, backing the chassis until the rear of thecontainer is aligned with the loading dock; and locking the bar of theU-shaped member to a locking structure of the loading dock.

The method can further include the steps of unlocking the bar of theU-shaped member from the locking structure of the loading dock; swingingthe U-shaped member upwardly to the extended horizontal position; andpushing the U-shaped member inward towards the chassis to the stowedposition.

The method can further include the step of drawing the U-shaped memberaway from the rear of the chassis by releasing a securing mechanismholding the U-shaped member in the stowed position.

The invention further comprises a loading dock locking system forconnection to a vehicle having a body with an elevated cargo space and aslideout liftgate, comprising a U-shaped member having at least oneelongate arm and a bar connected to a distal end of the elongate arm,the bar configured to be locked to the loading dock. The U-shaped memberis capable of being mounted to the body to be movable between a stowedposition such that the arm is positioned under or within the body,having the U-shaped member oriented approximately parallel to a floor ofthe body, and a vertical locking position such that the arm is extendedfrom the body and is oriented approximately vertically downward awayfrom the body. Also, vertical locking position is rearward of theliftgate, whereby the U-shaped member can be moved to the verticallocking position without being blocked by the liftgate, and whereby whenthe U-shaped member is in the stowed position, the liftgate can bedeployed to provide a platform movable between abutting the elevatedcargo space and the ground.

The invention further comprises a loading dock locking system for achassis for an intermodal shipping container, comprising: a U-shapedmember having at least one elongate arm and a bar connected to a distalend of the elongate arm, the bar configured to be locked to the loadingdock. The U-shaped member is capable of being mounted to the chassis tobe movable between a stowed position such that the arm is positionedunder or within the chassis, having the U-shaped member orientedapproximately parallel to a floor of the chassis, and a vertical lockingposition such that the arm is extended from the chassis and is orientedapproximately vertically downward away from the chassis.

A process is provided for using a chassis having a liftgate and aloading dock locking system, where the liftgate can be retracted toavoid interfering with the loading dock locking system, and thecontainer can abut against the loading dock. To practice this method,the liftgate does not need to be a slideout liftgate, and the loadingdock locking system does not need to be the U-shaped member of thisapplication. The container then can be transported on the chassis to aretail location lacking an elevated loading dock. Goods can be unloadedfrom the container at the retail location by extending and using theliftgate, resulting in an empty container. The liftgate can then beretracted and the empty container can be transported to a loading dock.The container can abut against the loading dock and the chassis can belocked to the loading dock using the loading dock locking system. Thecontainer can then be reloaded.

The invention also includes a chassis as described above, furthercomprising a liftgate mounted under the body and forward of the verticallocking position, whereby the U-shaped member can be moved to thevertical locking position without being blocked by the liftgate, andwhereby when the U-shaped member is in the stowed position, the liftgatecan be deployed to provide a platform movable between abutting the floorand the ground.

As can be seen from the above, the invention is extremely valuablebecause it provides major advantages in shipping and distribution ofgoods and saves tremendous amounts of money. Because the chassis allowsa container to BOTH be locked to a loading dock, and also be loaded andunloaded without a loading dock using the slideout liftgate, severallinks in the normal chain of distributing goods, and the waste ofbackhaul of empty containers, can be virtually eliminated, intermodalshipping containers can be taken directly to retail locations anddirectly unloaded, even if no loading dock is available, through use ofthe slideout liftgate. This eliminates the need for warehousing,slotting, picking and delivery. Further, after the container has beenemptied, it can be loaded again with other goods, because it can belocked to a loading dock, thus greatly reducing the lost time and moneyof backhaul.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a view of a trailer having an embodiment of the loadingdock locking system of the present invention in a stowed position.

FIG. 2 provides a view of a trailer having an embodiment of the loadingdock locking system of the present invention in a vertical lockingposition.

FIG. 3 provides a side view of an embodiment of the present invention.

FIG. 4 provides a perspective view of an embodiment of the presentinvention.

FIG. 5 provides a view of an embodiment of the present invention engagedwith a loading dock restraining system.

FIG. 6 provides a schematic view of an embodiment of a safety system ofthe present invention.

FIG. 7 provides a side view of an embodiment of the present invention inoperation.

FIG. 8 provides a perspective view of an improved embodiment of thepresent invention (with a container mounted thereon shown in broken lineas environmental structure, not comprising a portion of the invention),with a slideout liftgate shown lowered to the ground.

FIG. 9 provides a perspective view of an improved embodiment of thepresent invention (with a container mounted thereon shown in broken lineas environmental structure, not comprising a portion of the invention),with the slideout liftgate shown in the raised position, abutting theelevated interior floor of the container.

FIG. 10 provides a perspective view of art improved embodiment of thepresent invention, (with a container mounted thereon shown in brokenline as environmental structure, not comprising a portion of theinvention), with the slideout liftgate in the retracted position and theU-shaped member shown in the lowered position.

FIG. 11 provides a perspective view of an improved embodiment of thepresent invention with the slideout liftgate in the lowered position.

FIG. 12 provides a perspective view of an improved embodiment of thepresent invention with the slideout liftgate retracted and the U-shapedmember in the lowered position.

FIG. 13 provides an elevational view from the rear of an improvedembodiment of the present invention with the slideout liftgate loweredto the ground.

FIG. 14 provides an elevational view from the rear of an improvedembodiment of the present invention with the slideout liftgate retractedand the U-shaped member in the lowered position.

FIG. 15 provides a perspective view from the front of the rear portionof an I beam and box beam of an improved embodiment of the presentinvention;

FIG. 16 provides a perspective view from the tear of an improvedembodiment of the present invention, with the pins for engaging theU-shaped member retracted, and the U-shaped member, bolster and otherstructure omitted for clarity.

FIG. 17 provides a perspective view from the rear of an improvedembodiment of the present invention, with the pins for engaging theU-shaped member extended, and the U-shaped member, bolster and otherstructure omitted for clarity.

FIG. 18 provides a side elevational view of an improved embodiment ofthe present invention (with a container mounted thereon, forklift,loading dock, dock restraint hook and dock leveler shown in broken lineas environmental structure, not comprising a portion of the invention)with the slideout liftgate retracted and the U-shaped member in thelowered position, abutting against a loading dock, being restrained bythe U-shaped member to the loading dock, and being unloaded by aforklift.

FIG. 19 provides a side elevational view of an improved embodiment ofthe present invention (with a container mounted thereon shown in brokenline as environmental structure, not comprising a portion of theinvention) with a slideout liftgate shown in the raised position,abutting the interior floor of the container.

FIG. 20 provides a side elevational view of an improved embodiment ofthe present invention (with a container mounted thereon shown in brokenline as environmental structure, not comprising a portion of theinvention) with the slideout liftgate in the lowered position.

FIG. 21 provides a side elevational view of an improved embodiment ofthe present invention (with a container mounted thereon and a sealingengagement apparatus and closed loading dock shown in broken line asenvironmental structure, not comprising a portion of the invention),with the slideout liftgate retracted and the U-shaped member in thelowered position, abutting against a closed loading dock, and beingrestrained by the U-shaped member to the loading dock.

FIG. 22 provides a rear elevational view of a conventional chassis witha container mounted thereon and having a platform extension (with theclosed loading dock and sealing engagement apparatus shown in brokenline for clarity), showing that the platform extension prevents the rearof the container from sealing against the periphery of a closed loadingdock.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of presently preferred embodimentsof the invention and does not represent the only forms in which thepresent invention may be constructed and/or utilized. The descriptionsets forth the functions and the sequence of steps for constructing andoperating the invention in connection with the illustrated embodiments.

Generally, the present invention concerns a mechanism to facilitate thelocking of a trailer to a loading dock. The mechanism is stowable, suchthat when the trailer is not secured to the loading dock, the mechanismis hidden away within, for example, the structure of the trailer. Thisconfiguration allows the present invention to not interfere with movablelift gates, crash barriers (rated and approved bumpers, among others),and other structures that are below or move below the floor of thetrailer.

The term “trailer” will be used herein to refer to any portion of avehicle or structure connectable to a vehicle that can be abutted to aloading dock. This may include semi-trailers, full trailers, a rearportion of a cargo box truck, an intermodal shipping container mountedon a chassis, and the like. The term trailer is a non-limiting term mayapply to any and all of these structures, among others.

When the present invention is implemented on the back of trailers, itallows the trailer to be loaded at a loading dock safely, while alsoallowing the trailer to have an adjustable lift for loading or unloadingat a non-loading dock site, such as on the street. Moreover, because theloading dock locking system is stowable, it need not be designed for carcrash situations where its downward protrusion can be dangerous. Assuch, traditional crash barriers and/or bumpers may be used and thetrailer need not be substantially modified to accommodate the presentinvention. However, in some embodiments, the loading dock locking systemmay be designed to have a width equal to the width of the rear of thevehicle (+/−10%), and may be designed to also operate as a crashbarrier. In such an embodiment, the loading dock locking system may bestowed when using a mechanical lift, and may be kept in a verticallocking position during driving and operation to act as both a crashbarrier and also a loading dock lock. Further still, the presentinvention may be retrofitted to existing trailers with only minor laborand material costs by making use of existing space below a deck of thetrailer and by attaching the invention to the structure of the trailer.

The loading dock locking system of the present invention may be formedby a U-shaped member that is movable from a stowed position where it isslid approximately horizontally into an area of the trailer, to avertical locking position where it extends from the trailerapproximately vertically downward at a rear end of the trailer. However,it should be understood that any structure capable of attachment to aloading dock's vehicle restraint system may be used without strayingfrom the scope of this invention. The term U-shaped member will be usedherein for simplicity with the understanding that the connectingstructure may be any shape without straying from the scope of theinvention. The U-shaped member provides an attachment point for, andtherefore can be used with, all types of vehicle restraint systems thatutilize a hook or other similar restraining member that engages with abar, loop, or similar structure.

The U-shaped member may move between these positions in any way, howevertypically it may slide and pivot between the two positions. The U-shapedmember may be secured in each position by, for example, pins, clamps,frictional structures, and the like. When in the vertical, lockingposition of the U-shaped member, the trailer may interface with aloading dock restraining system to be locked in place to the loadingdock via the U-shaped member. This prevents the vehicle's accidentalmovement away from the dock. This locking may be done by existing, priorart dock restraining systems mounted to, or adjacent to, the loadingdocks. For example, one common dock restraining system is the Dok-Lok®of the Carlson Company. While in most embodiments the U-shaped membermay be a unitary piece, in one embodiment it may be telescoping inlength, having more than one lengthwise piece that may slide into eachother to move between the stowed and locking positions.

The U-shaped member may be made of any materials resilient enough toattach the trailer securely to the loading dock restraining system.Materials of which the U-shaped member maybe made include, but are notlimited to: metals, plastics, wood, composite materials, ceramics, andthe like.

Further, the loading dock locking system may, in some embodiments,comprise a safety mechanism that may ensure that the loading docklocking system is in the stowed position before transport. In oneembodiment, the safety mechanism may be an alarm. In another embodiment,the safety mechanism may be a light on an instrumentation panel in thepassenger area. In still another embodiment, the safety mechanism may beany structure or controller configured to either apply the brakes of thetrailer, or otherwise lock wheels of the trailer in position to preventmovement of the trailer.

In a particular embodiment, the safety mechanism may apply the trailer'sbrakes at a certain predetermined speed of the trailer, which may allowthe trailer to be moved away from the loading dock slowly. In still afurther embodiment, the trailer brakes may be automatically applied whenthe trailer is moving at approximately three miles per hour if thesystem is not in the stowed position.

In one embodiment, the safety mechanism may be controlled by a physicalactuator biased in the braking position that, when actuated, releasesthe brakes or disables the safety mechanism. In this embodiment, whenthe locking system U-shaped member is drawn away from its fully securedstowed position, its physical absence will allow the actuator of thesafety mechanism to move to a braking position. This physical actuatormay be, for example, a button, lever, tab, or the like that can be movedto a free, non-braking position by the presence of the U-shaped memberin the stowed position. The physical actuator may also be tied to alocking pin that may hold the U-shaped member in the stowed position.

In another embodiment, a sensor may be used to detect a presence of theU-shaped member in the stowed position. This sensor may be electronicand may utilize an electronic and/or computerized safety system.

The present invention, in many embodiments, has the U-shaped memberslideably positioned in a substantially horizontal position (+/−15degrees) when in the stowed position within a housing formed by thetrailer or connected to a structure of the trailer. In a particularembodiment, when in the stowed position, the U-shaped member may beapproximately parallel to a floor of the trailer body. When a userwishes to move the device to the vertical locking position, a securinglock may be released (such as a pin, a clamp, detent, seat, or thelike). The user may then pull the U-shaped member outward away from arear of the trailer until it reaches its maximum extended position. TheU-shaped member, in one embodiment, may have a tab, flange,spring-loaded pin fitting into an aperture of the member, or the like toprevent it from being fully removed from the housing and to identify itsmaximum extended positon. The member may, at this extended position, bemovable to a vertical position (+/−15 degrees) about an axis defined atits proximal end opposite to the bar by the trailer. Once in thevertical locking position, it may be secured in place by, for example, alock, clamp, detent, seat, spring loaded tab fitting into a hole of themember, or the like. The user may then lock the distal end (having thebottom of the ‘u’) of the U-shaped member to the loading dock.

The present invention may be used in any manner and may be moved betweenthe stowed position for transport and vertical locking position forsecuring to the loading dock in a number of ways. In one embodiment ofuse, the vehicle having the loading dock locking system may bepositioned nearby to the loading dock. At this point, the U-shapedmember can be moved from the stowed position to the vertical lockingposition to allow the trailer of the vehicle to be connected to theloading dock. This may be done by, in this embodiment, drawing theU-shaped member horizontally outward and away from the rear of thevehicle. At a maximally extended position of the U-shaped member, itwill be in a horizontally extended position and will be prevented frommoving further in this direction. At this point, the U-shaped member maybe swung downward in a hinged manner about an axis at the proximal endof the arms opposite to the bar. Once the U-shaped member is swungdownward to a vertical positon, it may lock in place and be ready forinterlacing with the loading dock vehicle restraining system. Thetrailer may then be positioned abutting (or very close to) the loadingdock. When in position, the bar of the U-shaped member will be in properposition to interlace with the dock's vehicle restraining system. Onceinterlaced, the trailer will be prevented from any substantial movement.

When the trailer is finished being loaded, the dock's restraining systemmay be disengaged from the bar. At this point, the trailer may be slowlydrawn away from the loading dock. Once far enough away, the U-shapedmember may be returned to the stowed position. This may be achieved byreleasing or unlocking (depending on embodiment) the U-shaped memberfrom its vertical locking position. The U-shaped member may then beswung upwardly (in an opposite motion to the downward swinging) to thehorizontally extending position. Then from the horizontally extendingposition, the U-shaped member may be pushed inward toward the traileruntil it is fully in the stowed position.

The U-shaped member may be movable between the stowed position and thevertical locking position in any manner. For example, the movement maybe done manually by a user in one embodiment In another embodiment, anautomated system may move the U-shaped member between the stowed andvertical locking position. In the automated system embodiment, a motor,springs, pistons, drives, or other motive system may be used to achievethis movement. The motive system may be in communication with theU-shaped member.

Turning now to FIG. 1, a view of the present invention in the stowedposition is provided. A rear of a trailer 10 such as a semi-trailer,shipping container attached to a chassis, cargo box truck, or the likefor freight shipping and other transport is shown. The rear of thetrailer 10 has a door 11. Below the door is the bumper 12 and wheels 15.Between the bumper 12 and door 11 is the loading dock locking structure,with bar 14 and latches 13 being visible. The bar 14 is a lower part ofa U-shaped member (see FIGS. 2-4) that is movable between the stowedposition as shown in this figure and a vertical locking position. Whenin the vertical locking position, the U-shaped member (and thus thetrailer) may be locked in a secured position to a loading dock.

FIG. 2 shows another embodiment of the present invention in the verticallocking position. In this view, the U-shaped member can be seen whichcomprises bar 14 connecting to two approximately parallel arms 21 at thedistal ends of the arms 21. The bar 14, in this view, is approximatelyperpendicular to the arms 21, but it should be understood that the bar14 may be angled, curved, or the like, without straying from the scopeof the present invention. In this position, bar 14 and arms 21 arelocked in place as controlled by latch 13. A loading dock vehiclerestraining system (not shown) may connect to the bar 14 when thetrailer 10 is backed up to a loading dock, thereby holding the trailer10 in position relative to the loading dock.

FIG. 3 provides a side view of an embodiment of the loading dock lockingsystem of the present invention. In this view, the U-shaped member is inthe vertical position with arms 21 extending downward. The U-shapedmember is mounted below a floor 32 of the trailer storage area to thetrailer's structure. A gusset plate 31 extends from the floor downwardto provide support for the arms 21 when in the vertical position. Aplurality of apertures are formed in the arm 21. A front aperture 34 isto receive a pin when the U-shaped member is in the stowed position (seeFIG. 1). The pin may be a spring loaded pin that holds the U-shapedmember in place. This same pin may be used to secure arm 21 in thevertical extended position by fitting into the upper aperture 33. Athird aperture 33 is positioned approximately midway down the length ofthe arm 21. This aperture 33 can receive a second pin to lock the arm 21in the vertical position.

FIG. 4 provides a perspective view of an embodiment of the loading docklocking system of the present invention. In this view, U-shaped memberhaving bar 14 and arms 21 is shown in the vertical position. Apertures33 and 34 can be seen in each arm. Upper apertures 33 are receiving amain pin 41 and a secondary pin 42. Two channels 43 are shown, in thisembodiment as square tubing. Channels 43 may serve to guide theslideable U-shaped member when moving between the stowed and verticalextended position, in other embodiments, any structure may be used toguide the U-shaped member, such as a track, a roller, and the like,without straying from the scope of the present invention. Regardless ofembodiment, the structure required to retain the U-shaped member in thestowed position may be mounted to the vehicle's structural members, suchas beams, body, or other framing.

FIG. 5 provides a view of an embodiment of the present invention lockedin place to a loading dock. In this view, the trailer is backed upagainst a wall 51 of the loading dock. A vehicle restraining system 50is mounted to the wall 51 and connects to the bar 14 of the U-shapedmember when in its vertical locking position. As such, when the lockingstructure is connected to the U-shaped member, the trailer to which itis attached to is locked in position adjacent to the wall 51. Thisallows safe and reliable loading of the trailer without a danger of itaccidentally rolling away from the wall.

FIG. 6 provides a schematic view of an embodiment of a safety mechanismof the present invention. In this embodiment, the safety mechanism isconfigured to activate the braking system of the trailer if the arm 21of the U-shaped member is not contacting a switch 60 to ensure that itis fully in the stowed position. As such, the safety mechanism ensuresthat the trailer cannot be hauled away and taken on the road ways untilit is fully stowed. In one embodiment, the safety braking system mayactivate once the trailer is moving at a certain speed, to allow forsome movement of the trailer away from the loading dock to allow forpositioning of the trailer and to create enough space for the U-shapedmember to be moved to the stowed position. In one embodiment, the safetymechanism may allow movement of the wheels up to 10 mph before thebrakes are applied. In another embodiment, the safety mechanism mayallow movement of the wheels up to 5 mph before the brakes are applied.In yet another embodiment, the safety mechanism may allow movement ofthe wheels up to 3 mph before the brakes are applied.

As is shown in FIG. 6, arm 21 is slideably movable along its lengthwithin channel 43. When arm 21 is fully stowed, its proximal end willcontact switch 60, which is shown here as a button but can be any sortof physical actuator. Switch 60 is in communication (physical,hydraulic, pneumatic, electronic, or otherwise) with a braking system 62of the trailer. The braking system is then able to activate or, if theswitch 60 is depressed by arm 21, deactivate the brakes 63 on the wheel(s) of the trailer.

FIG. 7 provides a side view of an embodiment of the present inventionand the operability of this embodiment. In this view, the U-shapedmember is shown in solid lines in the vertical position with arms 21extending downward. The U-shaped member is mounted below a floor 32 ofthe trailer storage area to the trailer's structure. A plurality ofapertures are formed in the arm 21—a front aperture 34 and upperapertures 33. As is demonstrated by the curving arrow, the arm 21, andthe rest of the U-shaped member can move between the vertical lockingposition (shown in solid lines) to the horizontal maximum extendedposition (shown in broken lines). Once in this maximum extendedposition, the arm 21 and the rest of the U-shaped member can move alongan approximately horizontal plane into (and out of) channel 43 asindicated by the horizontal arrow. Once the U-shaped member issufficiently within channel 43, it will be in a stowed positionallowing, for example, use of a mechanical lift, access to under thevehicle, and the like.

FIG. 8 provides a perspective view of an improved embodiment of thepresent invention (with a container 128 mounted thereon shown in brokenline as environmental structure, not comprising a portion of theinvention), with a slideout liftgate 132 shown lowered to the ground.The U-shaped member 120 is mounted rearward of the bolster 122 of achassis for an intermodal shipping container 128. The bolster 122 is astructural member on the chassis that has twist locks on the right andleft ends to attach the shipping container 128.

FIG. 9 provides a perspective view of an improved embodiment of thepresent invention (with a container 128 mounted thereon shown in brokenline as environmental structure, not comprising a portion of theinvention), with the slideout liftgate 132 shown in the raised position,abutting the interior floor of the container.

FIG. 10 provides a perspective view of an improved embodiment of thepresent invention (with a container 128 mounted thereon shown, in brokenline as environmental structure, not comprising a portion of theinvention), with the slideout liftgate 132 in the retracted position andthe U-shaped member 120 shown in the lowered position.

FIG. 11 provides a perspective view of an improved embodiment of thepresent invention with the slideout liftgate 132 in the loweredposition. As can be seen, the bolster 122 has twist locks at the leftand right ends for attaching a container, and the central portionextends forwardly to provide room to accommodate the U-shaped member120. Conventionally, the chassis comprises two parallel I beams 126. Ifnecessary, portions of the I beams 126 can be cut away and substitutedwith box beams 124 near the rear to accommodate mounting of the U-shapedmember 132 (see FIG. 16). Optionally also, triangular gusset plates 130(see FIG. 18) can be provided on the I beams 126 for reinforcement ofthe box beams 124.

FIG. 12 provides a perspective view of an improved embodiment of thepresent invention with the slideout liftgate 132 retracted and theU-shaped member 120 in the lowered position.

FIG. 13 provides an elevational view from the rear of an improvedembodiment of the present invention with the slide-out liftgate 132lowered to the ground. Vertical gusset plates 140 are shown, thatinteract with a sliding lock pin tubular housing 148 having sliding lockpins 150 (see FIG. 16).

FIG. 14 provides an elevational view from the rear of an improvedembodiment of the present invention with the slideout liftgate 132retracted and the U-shaped member 120 in the lowered position.

FIG. 15 provides a perspective view from the front of the rear portionof one of the I beams 126 and box beam 124 of an improved embodiment ofthe present invention. Part of the I beam 126 has been cut away toaccommodate the slideout liftgate and the box beam 124 has been securedby bolts 142.

FIG. 16 provides a perspective view from the rear of an improvedembodiment of the present invention, with the sliding lock pins 150 forengaging the U-shaped member in the retracted position. As can be seen,the exterior vertical gusset plates 140 have ride tracks 138 forreceiving pins to the U-shaped member to guide the U-shaped member as itis extended and retracted. The sliding lock pin tubular housing ismounted on interior vertical gusset plates 141.

FIG. 17 provides a perspective view from the rear of an improvedembodiment of the present invention, with the sliding lock pins 150 forengaging the U-shaped member extended and engaged with apertures in theexterior vertical gusset plates.

FIG. 18 provides a side elevational view of an improved embodiment ofthe present invention (with a container 128 mounted thereon, forklift,loading dock, dock restraint book and dock leveler shown in broken lineas environmental structure, not comprising a portion of the invention)with the slideout liftgate 132 retracted and the U-shaped member 120 inthe lowered position, abutting against a loading dock 144, beingrestrained by the U-shaped member 120 to the loading dock 144 by a dockrestraint hook 146, and being unloaded by a forklift 134 on a dockleveler 136.

FIG. 19 provides a side elevational view of an improved embodiment ofthe present invention (with a container 128 mounted thereon shown inbroken line as environmental structure, not comprising a portion of theinvention) with a slideout liftgate 132 shown in the raised position,abutting the interior floor of the container.

FIG. 20 provides a side elevational view of an improved embodiment ofthe present invention (with a container 128 mounted thereon shown inbroken line as environmental structure, not comprising a portion of theinvention) with the slideout liftgate 132 in the lowered position with apallet 158 shown in broken line as environmental structure, notcomprising a portion of the invention.

FIG. 21 provides a side elevational view of an improved embodiment ofthe present invention (with a container 128 mounted thereon shown inbroken line as environmental structure, not comprising a portion of theinvention), with the slideout liftgate 132 retracted and the U-shapedmember 120 in the lowered position, abutting against a closed loadingdock, structured as a door in a warehouse 154 having a loading dock seal152, and being restrained by the U-shaped member to the loading dock 154by a dock restraint hook 146. As can be seen, the sealing engagementapparatus 152 sealingly engages the rear end of the container forloading and unloading.

FIG. 22 provides a rear elevational view of a conventional chassis witha container 128 mounted thereof and having a platform extension 156according to U.S. Pat. No. 5,827,037 to Wilson (with the closed loadingdock and sealing engagement apparatus shown in broken line for clarity),showing that the platform extension 156 prevents the rear of thecontainer from engaging with the sealing engagement apparatus 152 of aclosed loading dock 154.

While several variations of the present invention have been illustratedby way of example in preferred or particular embodiments, it is apparentthat further embodiments could be developed within the spirit and scopeof the present invention, or the inventive concept thereof. However, itis to be expressly understood that such modifications and adaptationsare within the spirit and scope of the present invention, and areinclusive, but not limited to the following appended claims as setforth.

What is claimed is:
 1. A loading dock locking system for connection to avehicle having a body with an elevated cargo space and a slideoutliftgate, comprising: a U-shaped member having at least one elongate armand a bar connected to a distal end of the elongate arm, the barconfigured to be locked to the loading dock; wherein the U-shaped memberis capable of being mounted to said body to be movable between a stowedposition such that the arm is positioned under or within the body,having the U-shaped member oriented approximately parallel to a floor ofthe body, and a vertical locking position such that the arm is extendedfrom the body and is oriented approximately vertically downward awayfrom the body; wherein said vertical locking position is rearward ofsaid slideout liftgate, whereby said U-shaped member can be moved tosaid vertical locking position without being blocked by said slideoutliftgate, and whereby when said U-shaped member is in said stowedposition, said slideout liftgate can be deployed to provide a platformmovable between abutting said elevated cargo space and the ground.
 2. Achassis for an intermodal shipping container having fittings and afloor, comprising: a body having twist locks to engage with saidfittings for retaining said container on said body; a plurality ofwheels connected to the body; a loading dock locking system connected tothe body at a rear of the body, the loading dock locking systemcomprising: a U-shaped member configured to be locked to a loading dock,the U-shaped member having at least one elongate arm and a perpendicularbar connected to a distal end of the elongate arm, the bar configured tobe locked to the loading dock; wherein the U-shaped member is movablebetween a stowed position for when the chassis is in transport such thatthe arm is positioned under or within the body, having the U-shapedmember oriented approximately parallel to a floor of the body, and avertical locking position for locking the chassis to the loading docksuch that the arm is extended from the body and is orientedapproximately vertically downward away from the body; and a liftgatemounted under said body and forward of said vertical locking position,whereby said U-shaped member can be moved to said vertical lockingposition without being blocked by said liftgate, and whereby when saidU-shaped member is in said stowed position, said liftgate can bedeployed to provide a platform movable between abutting said floor andthe ground.